1. Field
Embodiments of the present disclosure relate to a driving unit and a robot cleaner having the same, and more particularly, to a structure which improves a traction force of a driving unit.
2. Description of the Related Art
In general, a robot cleaner is an apparatus which automatically cleans an area to be cleaned by moving about in the area by itself and suctioning in foreign materials such as particles from a floor surface even without a user's operation.
Such a robot cleaner includes driving wheels for driving a robot cleaner body, and the driving wheels drive a robot cleaner body using a frictional force generated between the driving wheels and a floor surface being in contact therewith.
To generate the frictional force, a force which presses the driving wheels toward the surface is needed, and this is related to a traction force of the robot cleaner.
The traction force of the driving wheels has to be constantly maintained regardless of a state or a condition of the floor surface so that the robot cleaner maintains a constant driving performance on various floor conditions, such as a hard floor or carpet, and a floor where steps exist.
Although elastic members such as a tension coil spring have been conventionally used for pressing the driving wheels toward a floor surface, the elastic members have a big difference in a force which presses the driving wheels due to change in an elastic force depending on the displacement of the driving wheels.